Pile driver systems apparatus and method for driving a pile

ABSTRACT

Pile driver systems and apparatus and method for driving a pile are described wherein a hollow pile is driven into the earth with the employment of a massive piston freely movable in the pile bore and normally resting on the pile. An air gun repeater is placed below the piston within the liquid containing pile bore to generate powerful thrusts upon its actuation. The thrust heaves the massive piston upwardly under guidance by the pile bore wall. When the piston again descends under guidance from the pile bore wall, it generates a momentum which is dissipated on the pile to drive the pile into the earth. In a preferred embodiment a double action pile driver is obtained by utilizing the thrust from the air gun repeater to produce an initial advance of the pile into the earth followed by a second advance when the massive piston dissipates its momentum on the pile.

yUnited States Patent C helminski [451 Feb.29,1972

[54] PILE DRIVER SYSTEMS, APPARATUS AND METHOD FOR DRIVING A PILlE [72] Inventor: Stephen V. Chelminslti, West Redding,

Conn.

[7 3] Assignee: Bolt Associates, Inc., Norwalk, Conn.

[22] Filed: June 25, 1969 [21] Appl. No.: 836,309

1 s 6a iv L., fi

Duyster et al 6l/53.5 X

[5 7] ABSTRACT Pile driver systems and apparatus and method for driving a pile are described wherein n hollow pile is driven into the earth with thc employment of u mnssive piston freely movable in the pile bore und normally resting on the pile. An ulr gun repeuter is placed below the piston withln the llquld contnlnlng pile bore to generate powerful thruuts upon ltn uctuutlon. v'llw thrust heaves the massive piston upwardly under guidance by the pile bore wall. When the piston again descends under guidance from the pile bore wall, it generates a momentum which is dissipated on the pile to drive the pile into the earth. 1n a preferred embodiment a double action pile driver is obtained by utilizing the thrust from the air gun repeater to produce an initial advance of the pile into the earth followed by a second advance when the massive piston dissipates its momentum on the pile.

34 Claims, l0 Drawing Figures PILE DRIVER SYSTEMS, APPARATUS AND METHOD FOR DRIVING A PILE This invention relates to pile driver systems, apparatus and method for driving a pile into earth. More specifically, the invention relates to driving hollow piles into the earth with the use of a repetively activated powerful thrust producing highpressure gas abrupt discharge device known as an air gun repeater.

ln a copending application entitled Powerful Thruster Method and Apparatus Suitable for Driving a Member Such as an Anchor or Pile into the Earth, and Anchoring and Pile Apparatus", Ser. No. 799,449, filed on Feb. 14, 1969, an apparatus is disclosed wherein a tool, known as an air gun repeater, abruptly releases a powerful high pressure gaseous charge within a substantially incompressible liquid such as water to generate a large impulse that may be employed to drive a pile into soil. VAs described in the above-identified copending patent application, an air gun repeater is inserted in a hollow reaction barrel containing water and is charged with high-pressure air. Thereupon, the airgun repeater is actuated to release its high pressure charge of air abruptly and produce a powerful thrust. This manner of operation is repeated until the object has reached the desired depth of penetration. As disclosed therein fuel may be mixed with the charge". of air and burned within the air gun repeater for further-raising the pressure before the abrupt discharge,

The present invention comprises a significant improvement over the method and apparatus disclosed in the above referred to copending application, including the utilization of a piston weight of substantial mass placed within the bore of a hollow pile containing liquid, said massive piston weight being located above the air gun repeater. The pile driver system of this invention includes the hollow pile itself which is to be driven into the earth, and air gun repeater, and the piston weight. A supply lof pressurized air and electrical controls for the air gun repeater as well as means for supplying water to be placed in the` hollow of the pile are provided with auxiliary equipment such as described in the above identified copending application.

ln the operation of an illustrated embodiment of the pile driver system and method, the abrupt releaseof the air gun repeaters charge of high pressure gas generates an immediate, powerful thrust in the liquid. Downwardly directed cornponents of the thrust advance the pile into the earth. The upwardly directed thrust components in the pile driver according to this invention encounter the piston thereby raising the latter in a sudden jumplike manner to a substantial extent. The piston, after its upward jump, descends, generating therewith a large momentum which is dissipated on the pile to provide a second powerful, downwardly directed thrust at a time occurring after air gun actuation. These two powerful thrusts on the pile with each actuation of the air gun produce an unusual advance of the pile into the earth.

The employmentof the piston in the pile driver of this invention imparts an advantage in addition to the piston impact after air gun actuation. This advantage resides in thefact the initial impulse tends to loosen the` soil which increases the penetration ability. This sequence of impulses enhances the advance of the pile into the'earth. The raisingof the piston results in tuminproviding a high momentum of the descending piston with the associated advantagey of improved pile penetration into the earth.

A further advantage in the pile driver of this invention resides in its ability to utilize huge pistons exhibiting a great mass to facilitate pile driving operations.

The various objects, aspects and advantages of the present invention will be in part more fully pointed out and in part will be understood from the following description of illustrative embodiments of the invention, when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective side view of an embodiment of the pile driver apparatus in accordance with the invention used to emplace a platform above water supported by piles. The piles are driven through vertical cylindrical guides supported by buoyant tanks, the piles being driven into the sediment' below the water utilizing the method of this invention;

FIGS. 2, 3 and 4 are enlarged sectional views of a preferred embodiment of a pile driver apparatus in accordance with the invention and illustrate successive operational positions of the apparatus;

FIG. 5 is a sectional view of the pile driver of FIG. 2 taken along the line 5-5 in FIG. 2;

FIG. 6 is a sectional view of another pile driver apparatus in accordance with the invention;

FIG. 7 is a like view to that shown in FIG. 6, but illustrates a succeeding operative position of the piston after actuation of the air gun repeater;

FIG. 8 is a sectional view of a modified embodiment of the piston and pile driver method and system;

FIGS. 9 and l0 are partial sectional views of other embodiments of the invention utilizing relatively movable pile tips for piles. driven into the earth in accordance with the invention.

With reference to FIG. l, there is shown a floating platform l0 sized to hold vertical cylindrical guide tubes ll and including multiple buoyant tanks 13. The floating platform l0 is used to guide piles 12being driven. The piles'l2 may have any desired length to support an oil drilling rig platform (not shown) to be constructed thereon, with the final platform to be at a substantial height above normal sea level. For this reason, the piles l2 may be quite long, often reaching lengths of the order of 500 feet, of which 300 feet may have to be driven into the sedimentto provide thedesired support capability. Piles for this purpose may have large diameters such as 4 feet. In the FIG. l, the floating platform l0 is shown with two piles 12 emplaced within the sediment and pile I2 being installed.

Pile 12 is driven into the sediment by use of a massive piston 14 (See also FIGS. 2, 3, 4 and 5) sized to fit within the hollow of pile 12'. with an air gun repeater 16 attached to the bottom end of the piston 14. The piston 14 is shown resting on the bottom of pile l2 on a shoulder which is more clearly illustrated in FIG. 2. The piston is suspended from a crane 18 located on an adjoining vessel 20 moored directly alongside of the floating platform 10. The piston 14 is attached to the crane 18 with a sling 22. In other pile driving operations, the piston may be resting on a removable stop member on the upper end of the pile 12', as will be explained in relation with other figures. The vessel 20 is provided with an air compressor 24 and an air gun repeater electrical control apparatus 26 to supply the air gun repeater 16 through an airline 28 with highly pressurized air and to control the firing of the gun through an electrical firing control cable 30.

The airgun repeater 16 useable with the pile driver of this invention may advantageously be such as is described in my U.S. Pat. Nos. 3,310,128 and 3,379,273. The air gun repeater may be repetitively operated, each time abruptly releasing a charge of very high pressure gas, eg., compressed air, supplied throughv airline 28 under remote control via electrical cable 30. The high pressure compressed air as supplied through the airline 28 from the compressor 24 typically charges the air gun repeater with air at high-pressures, for example, in the range from 1,000 to 3,000 pounds per square inch; however, higher or lower pressures may be used. The actual pressurefemployed to operate the air gun repeater depends upon the size of the air gun repeater and the piston and provides a convenient parameter for control of the operation.

It should be especially noted that the air gun repeater is operated while submerged in liquid such as water. Therefore, a hose 32 supplies water to the hollow of the pile l2 from a waterpump 34 located on the vessel 20.

With further reference to FIGS. 2, 3 and 4, the method of pile driving and details of the system and apparatus are more clearly shown. The pile 12 is provided with a longitudinal bore 42 extending from an upper open end 44 to terminate in the vicinity ofthe bottom end of the pile. The bore 42 is provided with a bottom closure in the form of a tip 46 which is welded onto the pile 12 and is provided with an annular shoulder 48 sized to fit into the bore 42 of the pile to absorb the large impulse of the pistons downward momentum. The height of the shoulder 48 is selected to be longer than air gun repeater 1,6, which freely fits within the bore of the annular shoulder 48 without contact with the tip 46. The wall thickness of the annular shoulder 48 is selected to be capable of absorbing piston impacts, and this shoulder 48 may be welded to the tip as indicated at 49, before the tip is inserted into the pile. 'I'he tip 46 is welded to the pile around the periphery as indicated at 50 to provide firm attachment between the pile 12' and tip 46. This tip attachment must be sufficiently strong to avoid dislodgment during operation.

The piston weight 14 is of general cylindrical cross section like that of the pile bore 42 and of substantial longitudinal dimension to obtain a large mass. For a l2 inch cylindrical bore 42, the piston, for example, has a length of 20 feet and a diameter of ll inches and is made of solid steel with an axial passage 52 extending longitudinally therethrough for accommodating the air line and electrical cable. This size piston has a substantial weight of the order of 6,000 pounds. The air gun repeater which has been employed to advantage with this size of piston has a chamber with a volume of 120 cubic inches, which is charged with high pressure air, for example in the range from 1,000 p.s.i. to 3,000 p.s.i. It will be understood that other sizes of chamber volumes and other levels of air pressure may be utilized depending upon pile sizes and soil conditions. This specification sets forth above and hereinafter the sizes which I have found to work to advantage for driving piles into a gravel bed located beneath salt water, a difficult to penetrate soil condition.

When it is desired to utilize such a piston 14 for driving piles having an internal diameter somewhat larger than l2 inches, then annular guide shoes are bolted around the bottom and top ends of the piston to provide appropriate guiding action and clearance. Such guide shoes have an axial length of 1 foot. Thus, this 6,000 pound piston 14 can be employed to drive piles having an internal diameter up to 28 inches.

For driving piles having an internal diameter in the range from 28 inches up to approximately 48 inches, there is employed a piston weight 2 feet in diameter and 16 feet long, weighing of the order of 25,000 pounds. The air gun repeater 16 utilized to advantage with this piston has a chamber volume in the range from 300 cubic inches to l,000 cubic inches, which is charged with high pressure air, for example, in the range from 1,000 p.s.i. to 3,000 p.s.i. As discussed above, guide shoes are bolted to the lower and upper ends of such piston to provide appropriate guiding action and clearance.

For driving piles having an internal diameter in the range from 4 to l0 feet, there is employed a piston weight having a diameter of 44 inches and which is 20 feet long with a weight of the order of 120,000 pounds. The airgun repeater utilized with such piston weight has a chamber volume in the range from l to l cubic feet, and is charged with high-pressure air, for example in the range from 1,000 to 3,000 p.s.i.

The annular clearance space 5l around the massive piston 14 is a predetermined amount sufficient to allow the escape of the gas which has been abruptly released beneath the piston. This clearance space 5l must not be too large, because it will then allow the high pressure gas to escape too rapidly before heaving the piston upwardly. Also, this clearance space 51 must not be too small, because it will then unduly restrict the escape of this gas. A differential of about l inch between the internal diameter (LD.) of the pile bore 42 and the outside diameter (O D.) of the piston, providing a clearance of ze inch on each side, works to advantage when driving piles having an l.D. of l foot and over when using a piston with a cylindrical configuration, i.e., without guide shoes.

Because of the fact that such guide shoes as discussed above, extend along the piston for only a fraction of its overall length, the clearance between the exterior surface of the guide shoes-and the bore of the pile is typically Vs inch to, A inch on each side, i.e., a differential in diameters of one-quarter to one-half of an inch, thus providing proper guiding action while allowing suitable escape of the high pressure gas.

The guide shoes may be ring-shaped, or instead they may be segments of a circle with sufficient vertical gaps between seg ments to allow escape of the high pressure gas.

The piston 14 is provided with a central through bore 52 for accommodating the firing control cable 30 and air line 28. The air gun repeater 16 is located adjacent to the lower end of the bore 52 for connection to the electrical cable and airline. The airgun repeater 16 is firmly mounted and affixed to the bottom end of the piston weight 14 by a flange 54 and boltsl 56. A counter bore S8 is provided to accommodate a solenoid valve 60 attached to the air gun repeater 16 and an airline connector 62.

With the location of the air gun repeater 16 in the manner shown in FIG. 2, the bottom end of the piston weight 14, the tip 46 of the pile 12' and the annular shoulder 48 define a chamber 64 containing liquid wherein the air gun is actuated. A liquid supply conduit 66 formed in the piston 14 terminates in chamber 64 to supply water thereto and maintain the air gun submerged. Also, the flow of water down through the conduit passage 66 serves to purge any trapped air out of the chamber 64 before the air gun repeater 16 is actuated therein. A check valve 68 is placed at the end of the conduit 66 and is operatively oriented to close in response to air gun actuation and thereby prevent transmittal of the high impulse through the water hose to the water pump. Thus, the water hose 32 and the water pump 34 connected thereto are isolated from this abrupt pressure impulse.

The piston weight 14 is freely mounted within the bore 42 with appropriate clearance 51 as discussed above. When the piston weight 14 is resting upon the shoulder 48, the sling 22, the cable and airline 30-28, as well as the flexible water hose 32 are loose with sufficient play to accommodate pile advances into the earth.

In operation of the pile driver system of FIG. 2, the airgun 16 is actuated by a suitableelectrical signal applied to the solenoid valve 60. The solenoid valve 6 0 in turn causes an abrupt release into the water filled chamber 64 of a gaseous charge, e.g., compressed air, stored in the airgun chamber.

The gaseous discharge produces a huge thrust which is transmitted in all directions because of the incompressibility of the water. Downwardly directed components of this thrust or impulse act on the tip 46 as indicated by the arrows 72 in FlG. 3.

YThe pile tip 46 responds with an advance into the sediment or earth as illustratively suggested in FIG. 3 and effectively pulls" the entire pile 12 down into the soil. At the same time the upwardly directed portion of the impulse as indicated'by the arrow 74 drives the piston weight 14 upwardly under guidance from the bore wall away from the tip 46.

When the initial impulse has effectively been dissipated, the piston weight 14 descends again under guidance by the pile bore wall toward the tip 46, as indicated by arrow 76 in FIG. 4, a high piston momentum is attained, which is transmitted to the pile l2' as an impulse by impact on the shoulder 48 of tip 46. The dissipation of the piston momentum is accompanied with a second advance of the pile 12' into the sediment as illustratively suggested in FIG. 4, thus again pulling the entire pile down into the soil.

Advantageously, this method, system and apparatus serve to drive the hollow pile l2' in tension because the impulses are l applied at the lower end of the pile so as to pull" it down into the soil. Two advantages are provided: (l) a thinner walled pile may be driven into the soil than when hammer blows are applied to its upper end, as is conventionally done, because the stresses imposed by this novel method are in tension rather than compression as is conventional. (2) The sudden tensile impulses which are transmitted upwardly along the pile wall cause the pile wall to contract slightly in accordance with Poisson's ratio, thus facilitating penetration by causing momentary shrinkage which reduces friction against the surrounding soil. ln a conventional pile driving operation the compressional blows at the top cause the pile wall momentarily to expand which tends to impede penetration.

Moreover, two driving impulses are obtained from each actuation of the air gun repeater 16. These two driving impulses were described above, but it may be helpful to the reader to summarize them: (l) The first driving impulse occurs upon the abrupt discharge of the air or other gases into the liquid lled chamber 64. This abrupt discharge also heaves the massive piston weight upwardly within the bore 42. (2) The second driving impulse of the sequence occurs a short time interval later when the massive piston weight falls down and impacts against the annular shoulder 48.

There are further mutually interrelated factors which cooperate to enhance the effectiveness of this method, system and apparatus. The first driving tension impulse of the sequence serves to agitate the soil surrounding the pile thus tending to reduce the impedance of the soil when the second driving tension impulse is applied soon afterward.

In addition, it is noted that the piston weight 14 is enabled to fall relatively freely down through the bore 42. The high pressure gas discharge rapidly expands so that its pressure drops quickly to a low value. Substantial amounts of the gas and water blast upwardly through the clearance space 51 as indicated at 81 in FIG. 4, before the piston weight reaches the high point of its travel. Thus, when it begins to fall back down, there is not much gas or liquid beneath it to check its substantially free fall.

As the piston 14 comes to rest on the shoulder 48 air bubbles remaining in the chamber 64 are permitted to escape through suitable apertures 78 at the top of the chamber 64. These apertures are formed by providing a series of recesses in the upper end of the shoulder 48 so that air may escape through these apertures and the annular clearance 51. After waiting a suitable time for the escape of the air bubbles from the chamber 64 aided by the purging refilling of the chamber 64 with water from the conduit 66, the air gun repeater is again actuated, and the double impulse sequence drive action of the pile is repeated. This procedure is continued until the pile has penetrated the soil to the desired depth.

FIG. 5 illustrates a cross section of the pile and piston of FIG. 2. The piston 14 is spaced from the pile inner wall with a clearance 5l as discussed in detail above. The piston is formed of a solid steel cylindrical member. The water conduit 66 and the cable conduit 52 are formed by drilling suitable passages at the desired locations during the formation of the piston.

One may appreciate that the liquid flow restrictive relationship between the piston 14 and the wall of the bore'42 of the pile can be altered also by the effective length of the piston weight 14. For instance, by making the piston 14 very long, the fluid resistance as seen from the bottom end of the piston upon the high-pressure gas discharge may be quite large even though the clearance 51 is substantial. Hence, the length of the piston to some extent determines the size of the clearance 51.

The advantages in the employment of a piston may be especially appreciated in consideration of an actual hollow pile having a l2 inch diameter bore 42 with a length of about 50 feet. A solid iron piston of about feet in length and ll inches in diameter advanced the pile 36 inches into a gravel soil beneath salt water with twenty-one actuations of the air gun. The driving of a conventional sheet-type pile into the same gravel soil with a conventional pile driving hammer resulted in but slight penetration accompanied with substantial deformation of the top end of the sheet pile. The relative ease with which the tipped hollow pile was driven into the gravel bed was found to be most remarkable.

With reference to FIG. 6, a hollow pile 40 is provided with a piston 84 having a top flange 86 sized to seat upon the top end of the pile. The bottom end of the piston 84 is, like the piston 14 of FIG. 2, provided with an airgun repeater 16. Depending from the piston flange 86 is an annular shroud 88. The shroud 88 may be formed of metal and is spaced from the pile 40 by a substantial clearance 89. A tip 92 is employed to close the bore 42 of the pile 40. The tip 92 is of simpler construction than tip 46 of the embodiment in F IG. 2, since the shoulder 48 used with the pile driver method and system of FIG. 2 is not needed. The tip 92 if provided with a centrally located bore 94 sized to snugly receive the'bottom end of the pile 40. The tip 92 is then peripherally weided to thepile 40 as indicated at 96.

The operation of the pile driver of FIG. 6 is like that of the apparatus shown in FIG. 2. Thus, as illustrated in the FlG. 7, actuation of the air gun produces a water transmitted downward thrust on the pile tip 92 and raises the piston 84..

The immense impulse produced by the air gun repeater 16 also is accompanied with a powerful emission of water from the annular clearance 51. The inclusion of the shroud 88 prevents a large vertical ejection of water.

When the piston 84 commences its descent, it gains a large momentum which is transmittedas an impulse to the pile l when the flange 86 strikes against the upper pile end. HG. 8 illustrates an embodiment including a removable stop 86 formed by a massive collar comprised of plurality of arcuate segments secured together by bolts 89. The collar 86 seats in an annular channel 87. Note that the removable stop flange 86 may fit like a collar at an intermediate position along the piston 84.

In the embodiments of FIGS. 6, 7 and 8, when it is desired to use the piston weight 84 with a pile having a larger internal diameter then guide shoes are attached around the lower end of the piston weight 84, such as discussed further above. Other guide shoes are also bolted to the interior surface of the upper end of the pile 40. ln this manner the lower end of the pile is guided by its attached shoes while the upper portion of the piston is guided by freely sliding clearance within the shoes attached to the pile bore at its upper end.

Instead of using a notch 78 in the top of the pile, as shown in FIGS. 6, 7 and 8, a bleed hole 78' may be provided to allow escape of any remaining air or other gas, after the piston weight 84 has seated on top of the pile.

FIGS. 9 and l0 illustrate alternate pile tip arrangements. Both tip arrangements provide a tip which is movable relative to the pile though captured therewith to prevent loss dun'ng the pile driving operation. The advantage of these tip arrangements lies in the ability of the piston weight 14 to drive the pile tip semiindependently. This method is especially useful in areas where the soil or sediment is hard, allowing the tip to penetrate first, then pulling the pile in after it in successive steps. In FIG. 9, the tip 98 is provided with an annular shoulder 48 sized to engage with the piston weight 14 at its upper end. The tip 98 is further provided with an outer annular sleeve 100, sized to freely receive an enlarged end of the pile. The end of pile 40 is enlarged by welding thereto a radially outward facing ring 102 before insertion in the interior of the sleeve 100. AFter the insertion of the end of the pile, a retainer ring 104 is welded on the sleeve to capture the pile 40 and ring 102 within the sleeve.

The tip 106 in FIG. l0 captures the pile 40 by providing an annular shoulder 108, the upper end of which serves to engage with the piston weight 14. The lower end of the shoulder 108 is recessed at l l0 to receive a radially inwardly facing retainer ring E12 welded to the pile 40. The tip 106 is mounted on the pile 40 by fiist placing the annular shoulder 108 as a separate component in the pile bore 42, then welding the retainer ring 112 to the pile, followed by the welding of the annular shoulder 108 at 114 to the lower end of the tip 106.

As an alternative embodiment, it is noted that the annular stop shoulder 48 can be secured by lwelding to the lower end of the piston weight 14 instead of being secured to the lower end of the pile. In this alternative embodiment the annular stop shoulder surrounds die air gun repeater 16 and projects down below it. Thus, when the piston descends the impact occurs between the lower end of this annular stop shoulder and the tip 46.

It is to be understood that the air gun repeater 16 may include provision for mixing fuel with the high pressure air therein and for burning this fuel to further raise the pressure before the abrupt discharge of the airgun repeater. Instead of using compressed air, it is possible to use other gases such as compressed carbon dioxide, compressed nitrogen, and so forth. Thus, the term abrupt discharge of high pressure gas pressure or gas pressure as explained in detail in my U.S. Pat.

After the pile has been driven, the piston weight 14 or 84 and the air gun repeater 16 are removed by lifting with the crane 18 and sling 22 to be used again. Thereafter, the bore 42 of the pile can be filled with concrete. As noted above, this method, system and apparatus enable thinner walled piles to be driven, if desired, which are thereafter filled with concrete to provide additional rigidity, ln addition this invention enables larger diameter piles to be driven, for example up to l feet in diameter. After such large diameter piles have been driven, their interiors may be used as reservoir chambers or tanks for temporarily storing petroleum or natural gas, as may be desired.

Although FIG. 1 shows the pile driver system of this invention in use for the installation of a platform above a body of water, the utility of the pile driver method, system and apparatus is much broader and generally is to be considered applicable whenever a hollow pile is to be installed. High pile penetration rates may be achieved even under high soil resistances. The pile driver of this invention is especially suitable in driving enormous piles deep into the earth. Huge pistons may be employed with larger diameter piles and quite simply actuated in the manner of this invention to provide an efficient pile driver.

What is claimed is:

l. A method of driving a hollow pile into the earth comprising the steps of placing a hollow pile in the desired position relative to the earth, maintaining a liquid within the hollow of the pile, providing an impulse within the liquid in the pile to generate a powerful thrust to impart an initial advance of the pile into the earth, converting the upwardly directed thrust into a substantial momentum, dissipating this momentum on the pile in a direction to further drive the pile into the earth, waiting a brief time interval for settlement of the liquid, providing a second impulse within the liquid in the pile to generate a second powerful thrust to again initially advance the pile into the earth and converting the upwardly directed second thrust into a substantial momentum, again dissipating this momentum on the pile to further drive the pile into the soil, and repeating said steps until the pile has been driven into the earth to a desired depth.

2. A method of driving a hollow pile into the earth as claimed in claim l in which said impulses are provided within the liquid in the pile near the lower end of the hollow pile to generate powerful thrusts to pull the pile into the earth.

3. A method of driving a hollow pile into the earth as claimed in claim 2 in which the momentum is dissipated near the lower end of the pile to generate a second powerful thrust to pull the pile into the earth.

4. A method of driving a hollow pile into soil comprising the steps of placing a hollow pile in the desired position relative to the earth, providing a liquid within the hollow of the pile, abruptly releasing high-pressure gas within the liquid to generate a powerful thrust to advance the pile into the soil, converting said thrust into substantial momentum of a piston weight located in the hollow of the pile, dissipating the momentum of said piston weight on the pile in a direction to further drive the pile into the soil, waiting a brief time interval for settlement of the liquid, again releasing high-pressure gas within the liquid to generate a second powerful thrust to further drive the pile into the soil, converting the second thrust into a substantial momentum of said piston weight, again dissipating the momentum of said piston weight on the pile to further drive the pile into soil, and repeating said steps until the pile has been driven into the soil to a desired depth.

5. A method of driving a hollow pile into the earth comprising the steps of introducing liquid into the bore of the hollow pile, placing a massive piston weight in the bore,`repeatedly abruptly discharging high-pressure gas into the liquid in the bore beneath said massive piston weight for creating powerful impulses in the liquid in the bore beneath said massive piston weight for repeatedly pushing said massive piston weight upwardly, and thereafter allowing said massive piston weight to descend in the bore for driving the hollow pile into the earth.

6. A method of driving a hollow pile into the earth comprising the steps of introducing liquid into the bore of the hollow pile, placing a massive piston weight in the bore, repeatedly creating powerful impulses in the liquid in the bore beneath said massive piston weight for driving the hollow pile into the earth in which said powerful impulses are repeatedly created by abruptly releasing high-pressure gas into the liquid in the bore beneath said massive piston weight, and further liquid is introduced into the bore beneath said massive piston weight following the abrupt release of high-pressure gas for replacing the liquid and purging the gas from the bore beneath said massive piston weight.

7. A method of driving into the sediment beneath a body of water comprising the steps of providing a member having a longitudinally extending bore, introducing liquid into said bore, positioning a massive piston weight in said bore relatively movable upwardly and downwardly with respect to the bore wall, and abruptly releasing pressurized air beneath said massive piston weight generating powerful impulses in the liquid within said bore beneath said relatively movable massive piston weight repeatedly raising said massive piston weight in a sudden, jumplike manner producing driving thrusts for driving into the sediment beneath a body of water.

8. A method of driving into the earth beneath a body of water comprising the steps of placing a hollow member containing a liquid and having a longitudinal bore member in the desired position relative to the earth, releasing into the liquid a high-pressure gas impulse from an air gun repeater located below a massive piston movable within the bore and normally resting on the member to upwardly heave the piston under vertical guidance by the bore wall, permitting the upwardly heaved piston to drop under guidance by the bore wall and dissipate piston momentum on the member to drive into the earth, waiting a brief interval for return of liquid within the bore, releasing into the liquid a second high-pressure gas impulse from the air gun repeater to again upwardly heave the piston under guidance of the bore wall and permitting the upwardly heaved piston to drop under guidance by pile bore wall to dissipate piston momentum on the member to further-drive into the earth, and repeating said steps until the driving operation is completed.

9. The method of driving into the earth beneath a body of water as claimed in claim 8 wherein said high pressure gas impulses are released into the liquid within the bore below a massive piston normally resting on said hollow member near the lower end thereof.

l0. The method of driving into the earth beneath a body of water as claimed in claim 8 wherein said high-pressure gas impulses are released into the liquid within the bore below a massive piston normally resting on said hollow member near the upper end thereof.

11. A pile driver system comprising a pile having a longitudinal bore commencing at an upper end of the pile, said bore containing a liquid, a piston of substantial weight mounted to move relative to the pile within the bore and shaped to t with predetermined fluid flow restrictive relationship with the wall of the pile bore, an air gun repeater located within the pile bore beneath the piston and positioned for abruptly releasing high-pressure gas within the pile bore below the piston within the liquid in the pile bore, means for pneumatically charging said air gun repeater, and means for repetitively abruptly releasing high-pressure gas from the airgun repeater to drive the pile into soil.

l2. The pile driver system as claimed in claim l1 wherein the pile at the lower end thereof is provided with a bore closing tip defining a chamber sized to receive the air gun repeater therein with said chamber bounded by an annular shoulder sized for impact support ofthe piston weight.

13. The pile driver system as claimed in claim'll in which said air gun repeater is attached to said piston weight near the lower end thereof, an annular shoulder surrounding said air gun repeater defining a chamber containing liquid into which said high-pressure gas is abruptly released.

14. The pile driver system as claimed in claim 13 in which said annular shoulder is attached to the lower end of said piston weight.

l5. A pile driver as claimed in claim 11 wherein the piston weight is provided with a longitudinal liquid supply passage to supply liquid to the pile bore portion below the piston.

16. A pile driver as claimed in claim 15 wherein the piston weight is further provided with a check valve operatively connected with the liquid supply passage to check the upward flow of liquid through the supply passage upon the abrupt release of high-pressure gas into the liquid below said piston weight.

17. A pile driver comprising a pile having a longitudinal bore commencing at an upper end of the pile, pneumatically energized high-pressure air releasing apparatus located in the bore for suddenly releasing high-pressure air in the bore, and a massive piston of substantial weight movably mounted for upward and downward motion relative to the pile, said massive piston weight being located in the bore between the apparatus for suddenly releasing high-pressure air and the upper end of the bore, said movable piston weight normally and effectively resting on the pile and being raised in a sudden jumplike manner by said sudden release of high-pressure air.

18. A pile driver system comprising a pile having a longitudinal bore commencing at ari upper end and bottoming in the4 vicinity of the lower end of the pile, an air gun repeater located in the bore, and a massive piston movably mounted in the bore between the airgun repeater and the upper end of the bore and having a mass selected to provide a large momentum in response to impulses generated by the airgun repeater, said massive piston normally effectively resting on the pile to dissipate its momentum on the pile, said bore containing liquid sufficient to submerge the airgun repeater.

19. A pile driver system as claimed in claim 18 wherein the air gun repeater is mounted to the massive piston at the lower end thereof.

20. A pile driver system as claimed'in claim 19 wherein the pile includes a bottom end tip and a massive piston support shoulder extending along the pile bore around said air gun repeater for a length sufficient to maintain the air gun repeater free of direct contact with the tip.

21. A pile driver system as claimed in claim 20 wherein vthe tip is permanently affixed to the pile.

22. A pile driver system as claimed in claim 20 wherein the pile tip is slidably mounted to the pile in captured relationship therewith.

23. A pile driver system as claimed in claim 22 wherein said annular shoulder is affixed to said tip and said annular shoulder is provided with a recess extending radially inwardly and having an axial length selected commensurate with the desired slidable movement between the pile and the tip, and a retainer ring attached to the pile end located within said recess and mounted within the pile bore, said retainer ring having a radial thickness sufficient to capture the tip to the pile.

24. A pile driver as claimed in claim 22 wherein the pile tip is provided with an outer annular sleeve having a through bore sized to freely enclose an end portion of the pile, a first ring affixed within said sleeve at the end thereof away from the tip, and a second ring affixed to the pile end at the radially outer surface thereof', said first and second rings having radial thicknesses sufficient to capture the tip to the pile with limited sliding motion therebetween.

25. A pile driver system as claimed in claim 19 wherein the massive piston is provided with a stop flange sized to seat the piston onto the upper end of the pile with the piston havin a portion extending within the'pile bore and being longitudinaly movable therein.

26. A pile driver system as claimed in claim 25 wherein the piston is further provided with shroud sized to enclose a selected portion of the upper end of the piston, said shroud having a length sufficient to deflect ejected liquid downwardly.

27. A pile driver system as claimed in claim 26 wherein the shroud extends down from said stop flange alongside of the outer surface ofthe upper end ofthe pile.

28. Apparatus for driving a member into the earth comprising means defining a bore, a massive piston weight located in said bore and being movable upwardly and downwardly in said bore, means for suddenly providing high-pressure gas in said bore beneath the lower end of said massive piston weight for raising said massive piston weight in a jumplike manner, and supply means extending to said high pressure gas providing means for supplying high pressure gas thereto.

29. Apparatus for driving a member into the earth as claimed in claim 28 in which said massive piston weight has guide shoes affixed thereto for guiding said piston along the wall of said bore.

30. Apparatus for driving a member into the earth comprising a massive piston weight having a passage extending longitudinally therethrough, means for abruptly releasing high pressure gas in the region beneath the lower end of said mas' sive piston weight, pump means for pumping liquid through said passage into the region below said lower end, and supply and control means extending to said sudden high pressure gas releasing means.

31. Apparatus for driving a member into the earth comprising a massive piston weight, an air gun repeater for abruptly releasing high-pressure gas beneath the lower end of said massive piston weight for causing said massive piston weight to jump upwardly for providing a downward thrust suitable for driving the member into the earth, and supply means extending down past said massive piston weight to said air gun repeater for supplying compressed air thereto.

32. Apparatus for driving a member into the earth as claimed in claim 31 in which said massive piston weight has a passage extending longitudinally therethrough and said supply means is a compressed air line extending down through said passage.

33. Apparatus for driving a member into the earth as claimed in claim 3l in which said massive piston weight has an annular shoulder thereon surrounding said air gun repeater.

34. Apparatus for driving a member into the earth comprising a massive piston weight, an air gun repeater for abruptly releasing high-pressure gas below said massive piston weight, said massive piston weight having a passage extending longitudinally therethrough and supply means for feeding liquid down through said passage to surround said air gun repeater with liquid. v 

1. A method of driving a hollow pile into the earth comprising the steps of placing a hollow pile in the desired position relative to the earth, maintaining a liquid within the hollow of the pile, providing an impulse within the liquid in the pile to generate a powerful thrust to impart an initial advance of the pile into the earth, converting the upwardly directed thrust into a substantial momentum, dissipating this momentum on the pile in a direction to further drive the pile into the earth, waiting a brief time interval for settlement of the liquid, providing a second impulse within the liquid in the pile to generate a second powerful thrust to again initially advance the pile into the earth and converting the upwardly directed second thrust into a substantial momentum, again dissipating this momentum on the pile to further drive the pile into the soil, and repeating said steps until the pile has been driven into the earth to a desired depth.
 2. A method of driving a hollow pile into the earth as claimed in claim 1 in which said impulses are provided within the liquid in the pile near the lower end of the hollow pile to generate powerful thrusts to ''''pull'''' the pile into the earth.
 3. A method of driving a hollow pile into the earth as claimed in claim 2 in which the momentum is dissipated near the lower end of the pile to generate a second powerful thrust to ''''pull'''' the pile into the earth.
 4. A method of driving a hollow pile into soil comprising the steps of placing a hollow pile in the desired position relative to the earth, providing a liquid within the hollow of the pile, abruptly releasing high-pressure gas within the liquid to generate a powerful thrust to advance the pile into the soil, converting said thrust into substantial momentum of a piston weight located in the hollow of the pile, dissipating the momentum of said piston weight on the pile in a direction to further drive the pile into the soil, waiting a brief time interval for settlement of the liquid, again releasing high-pressure gas within the liquid to generate a second powerful thrust to further drive the pile into the Soil, converting the second thrust into a substantial momentum of said piston weight, again dissipating the momentum of said piston weight on the pile to further drive the pile into soil, and repeating said steps until the pile has been driven into the soil to a desired depth.
 5. A method of driving a hollow pile into the earth comprising the steps of introducing liquid into the bore of the hollow pile, placing a massive piston weight in the bore, repeatedly abruptly discharging high-pressure gas into the liquid in the bore beneath said massive piston weight for creating powerful impulses in the liquid in the bore beneath said massive piston weight for repeatedly pushing said massive piston weight upwardly, and thereafter allowing said massive piston weight to descend in the bore for driving the hollow pile into the earth.
 6. A method of driving a hollow pile into the earth comprising the steps of introducing liquid into the bore of the hollow pile, placing a massive piston weight in the bore, repeatedly creating powerful impulses in the liquid in the bore beneath said massive piston weight for driving the hollow pile into the earth in which said powerful impulses are repeatedly created by abruptly releasing high-pressure gas into the liquid in the bore beneath said massive piston weight, and further liquid is introduced into the bore beneath said massive piston weight following the abrupt release of high-pressure gas for replacing the liquid and purging the gas from the bore beneath said massive piston weight.
 7. A method of driving into the sediment beneath a body of water comprising the steps of providing a member having a longitudinally extending bore, introducing liquid into said bore, positioning a massive piston weight in said bore relatively movable upwardly and downwardly with respect to the bore wall, and abruptly releasing pressurized air beneath said massive piston weight generating powerful impulses in the liquid within said bore beneath said relatively movable massive piston weight repeatedly raising said massive piston weight in a sudden, jumplike manner producing driving thrusts for driving into the sediment beneath a body of water.
 8. A method of driving into the earth beneath a body of water comprising the steps of placing a hollow member containing a liquid and having a longitudinal bore member in the desired position relative to the earth, releasing into the liquid a high-pressure gas impulse from an air gun repeater located below a massive piston movable within the bore and normally resting on the member to upwardly heave the piston under vertical guidance by the bore wall, permitting the upwardly heaved piston to drop under guidance by the bore wall and dissipate piston momentum on the member to drive into the earth, waiting a brief interval for return of liquid within the bore, releasing into the liquid a second high-pressure gas impulse from the air gun repeater to again upwardly heave the piston under guidance of the bore wall and permitting the upwardly heaved piston to drop under guidance by pile bore wall to dissipate piston momentum on the member to further drive into the earth, and repeating said steps until the driving operation is completed.
 9. The method of driving into the earth beneath a body of water as claimed in claim 8 wherein said high pressure gas impulses are released into the liquid within the bore below a massive piston normally resting on said hollow member near the lower end thereof.
 10. The method of driving into the earth beneath a body of water as claimed in claim 8 wherein said high-pressure gas impulses are released into the liquid within the bore below a massive piston normally resting on said hollow member near the upper end thereof.
 11. A pile driver system comprising a pile having a longitudinal bore commencing at an upper end of the pile, said bore containing a liquid, a piston of substantial weight mounted to move relative to the pile within the bore and shaped to fit with predetermined fluiD flow restrictive relationship with the wall of the pile bore, an air gun repeater located within the pile bore beneath the piston and positioned for abruptly releasing high-pressure gas within the pile bore below the piston within the liquid in the pile bore, means for pneumatically charging said air gun repeater, and means for repetitively abruptly releasing high-pressure gas from the airgun repeater to drive the pile into soil.
 12. The pile driver system as claimed in claim 11 wherein the pile at the lower end thereof is provided with a bore closing tip defining a chamber sized to receive the air gun repeater therein with said chamber bounded by an annular shoulder sized for impact support of the piston weight.
 13. The pile driver system as claimed in claim 11 in which said air gun repeater is attached to said piston weight near the lower end thereof, an annular shoulder surrounding said air gun repeater defining a chamber containing liquid into which said high-pressure gas is abruptly released.
 14. The pile driver system as claimed in claim 13 in which said annular shoulder is attached to the lower end of said piston weight.
 15. A pile driver as claimed in claim 11 wherein the piston weight is provided with a longitudinal liquid supply passage to supply liquid to the pile bore portion below the piston.
 16. A pile driver as claimed in claim 15 wherein the piston weight is further provided with a check valve operatively connected with the liquid supply passage to check the upward flow of liquid through the supply passage upon the abrupt release of high-pressure gas into the liquid below said piston weight.
 17. A pile driver comprising a pile having a longitudinal bore commencing at an upper end of the pile, pneumatically energized high-pressure air releasing apparatus located in the bore for suddenly releasing high-pressure air in the bore, and a massive piston of substantial weight movably mounted for upward and downward motion relative to the pile, said massive piston weight being located in the bore between the apparatus for suddenly releasing high-pressure air and the upper end of the bore, said movable piston weight normally and effectively resting on the pile and being raised in a sudden jumplike manner by said sudden release of high-pressure air.
 18. A pile driver system comprising a pile having a longitudinal bore commencing at an upper end and bottoming in the vicinity of the lower end of the pile, an air gun repeater located in the bore, and a massive piston movably mounted in the bore between the airgun repeater and the upper end of the bore and having a mass selected to provide a large momentum in response to impulses generated by the airgun repeater, said massive piston normally effectively resting on the pile to dissipate its momentum on the pile, said bore containing liquid sufficient to submerge the airgun repeater.
 19. A pile driver system as claimed in claim 18 wherein the air gun repeater is mounted to the massive piston at the lower end thereof.
 20. A pile driver system as claimed in claim 19 wherein the pile includes a bottom end tip and a massive piston support shoulder extending along the pile bore around said air gun repeater for a length sufficient to maintain the air gun repeater free of direct contact with the tip.
 21. A pile driver system as claimed in claim 20 wherein the tip is permanently affixed to the pile.
 22. A pile driver system as claimed in claim 20 wherein the pile tip is slidably mounted to the pile in captured relationship therewith.
 23. A pile driver system as claimed in claim 22 wherein said annular shoulder is affixed to said tip and said annular shoulder is provided with a recess extending radially inwardly and having an axial length selected commensurate with the desired slidable movement between the pile and the tip, and a retainer ring attached to the pile end located within said recess and mounted within the pile bore, said retainer ring having a radial thickness sufficient to captUre the tip to the pile.
 24. A pile driver as claimed in claim 22 wherein the pile tip is provided with an outer annular sleeve having a through bore sized to freely enclose an end portion of the pile, a first ring affixed within said sleeve at the end thereof away from the tip, and a second ring affixed to the pile end at the radially outer surface thereof, said first and second rings having radial thicknesses sufficient to capture the tip to the pile with limited sliding motion therebetween.
 25. A pile driver system as claimed in claim 19 wherein the massive piston is provided with a stop flange sized to seat the piston onto the upper end of the pile with the piston having a portion extending within the pile bore and being longitudinally movable therein.
 26. A pile driver system as claimed in claim 25 wherein the piston is further provided with shroud sized to enclose a selected portion of the upper end of the piston, said shroud having a length sufficient to deflect ejected liquid downwardly.
 27. A pile driver system as claimed in claim 26 wherein the shroud extends down from said stop flange alongside of the outer surface of the upper end of the pile.
 28. Apparatus for driving a member into the earth comprising means defining a bore, a massive piston weight located in said bore and being movable upwardly and downwardly in said bore, means for suddenly providing high-pressure gas in said bore beneath the lower end of said massive piston weight for raising said massive piston weight in a jumplike manner, and supply means extending to said high pressure gas providing means for supplying high pressure gas thereto.
 29. Apparatus for driving a member into the earth as claimed in claim 28 in which said massive piston weight has guide shoes affixed thereto for guiding said piston along the wall of said bore.
 30. Apparatus for driving a member into the earth comprising a massive piston weight having a passage extending longitudinally therethrough, means for abruptly releasing high pressure gas in the region beneath the lower end of said massive piston weight, pump means for pumping liquid through said passage into the region below said lower end, and supply and control means extending to said sudden high pressure gas releasing means.
 31. Apparatus for driving a member into the earth comprising a massive piston weight, an air gun repeater for abruptly releasing high-pressure gas beneath the lower end of said massive piston weight for causing said massive piston weight to jump upwardly for providing a downward thrust suitable for driving the member into the earth, and supply means extending down past said massive piston weight to said air gun repeater for supplying compressed air thereto.
 32. Apparatus for driving a member into the earth as claimed in claim 31 in which said massive piston weight has a passage extending longitudinally therethrough and said supply means is a compressed air line extending down through said passage.
 33. Apparatus for driving a member into the earth as claimed in claim 31 in which said massive piston weight has an annular shoulder thereon surrounding said air gun repeater.
 34. Apparatus for driving a member into the earth comprising a massive piston weight, an air gun repeater for abruptly releasing high-pressure gas below said massive piston weight, said massive piston weight having a passage extending longitudinally therethrough and supply means for feeding liquid down through said passage to surround said air gun repeater with liquid. 